1. Field of Invention
This invention relates to a quick-release device that accommodates the interface connection of any camera-type device with any support device.
2. Description of Prior Art
Historically, manufacturers of cameras, lenses, or other optical devices have provided an aperture for attachment of a support device, such as tripods, monopods and ball heads, all having a threaded stud that accommodates their joining. The function of joining these devices has led to the development of products that quickly join or release the devices, known as a "Quick Release".
Typically, the quick-release system has developed around two basic design concepts, either plate and pocket or plate and slot (dovetail). In either concept, the base plate is to reliably hold the release plate and prevent any inadvertent release.
Traditionally, a release plate device must be attached to the camera, using the aperture as provided by the manufacturer. The always present problem is that of a single attach point being able to stop torsional twisting or loosening between the release plate and the camera.
The plates described in U.S. Pat. No. 5,725,187 to Vo (1998), U.S. Pat. No. 5,222,826 to Hankie (1993) and U.S. Pat. No. 4,929,973 to Nakatani (1990), reflect the most often used method, where twisting is prevented by inserting a second screw through the release plate. This second screw is then forced into the bottom surface of the camera, resulting in damage to surfaces not designed for indiscriminate penetrations. Conversely, U.S. Pat. No. 4,979,709 to Ishikawa (1990) and U.S. Pat. No. 5,429,332 to Ishikawa (1995) fail to address any method at all to stop unwanted torsional twisting between plate and camera.
Unfortunately, methods to stop torsional twisting have either been ignored or considered solved by introducing a second screw. However, a second screw is not acceptable by virtue of the resultant damage.
In general, all plate and pocket or the plate and slot design concepts do a reasonable job of holding the release plate once inserted into the base. Unfortunately, problems arise when the plate is released from the base by an accidental bumping or loosening of the clamping handle or lever. In fact, accidental loosening is so common some manufacturers only supply the clamping mechanism with the smallest round knob or the shortest lever. However, this approach is counter productive when trying to apply as much clamping pressure as possible as it is difficult to grip such small knobs or levers.
U.S. Pat. No. 5,725,187 to Vo (1998), U.S. Pat. No. 5,737,757 to Paddock (1998) and U.S. Pat. No. 5,429,332 to Ishikawa (1995) all suggest the use of small knobs or levers. Conversely, U.S. Pat. No. 5,230,490 to Sloop (1993) demonstrates the concern for inadvertent release by creating a complex system of cams, levers, springs, pins, and plates.
The underlying weakness of today's quick-release systems is the failure to provide a positive lock between the release plate and its base and to control torsional twisting between the release plate and the camera device.